A drug dealer was convicted today of supplying a gun to Mark Duggan only minutes before the police shooting that sparked the London riots.

The guilty verdict means the spark that led to millions of pounds of damage across the capital can be revealed as a deadly drunken nightclub row. Police intercepted Duggan because they feared he had armed himself to take revenge for the killing of a close friend, Kevin Easton.

Today at the Old Bailey a jury decided Kevin Hutchinson-Foster, 30, handed a pistol in a shoebox to Duggan 15 minutes before Duggan was shot dead by officers in Tottenham on August 4, 2011.

In January 2011, eight months before the riots, Easton and Warren Allen, who had been friends, fell out on a drunken night out in Old Jewry.

Three months later, Easton stabbed a close friend of Allen in the Boheme club in Mile End Road. Easton, 23, was then stabbed himself four times, including a thrust through his heart. He tried to escape down the stairs of the club but collapsed and died.

The underworld grapevine pointed to Allen, who had been in the club at that night, as the killer. But he was later cleared by a jury.

Duggan was shot after police stopped his minicab near Tottenham Hale station. He had emerged from the vehicle allegedly holding the weapon, a BBM Bruni Model 92. It was found five metres from the car, although Duggan’s family insist he was unarmed at the time.

Duggan’s fingerprints were found on the shoebox but neither his prints nor DNA were on the gun itself, which had been modified to fire 9mm bullets.

Statements from officers describing Duggan wielding the gun have angered his family before an inquest into his death due to start in September.

Hutchinson-Foster, 30 of Forest Gate, will be sentenced next month at the Old Bailey by Judge David Radford.

He had pleaded not guilty to passing Duggan the gun, but was convicted by a 10-2 majority at a second trial. The first, at Snaresbrook crown court, had failed to reach a verdict.

He had earlier admitted possessing the gun with intent to cause fear of violence a week before the police shooting, and using it to pistol whip barber Peter Osadebay.

In a separate trial, which can only be reported fully today, Allen was cleared of killing Easton.

He had gone on the run after Easton’s death before he was eventually tracked down to a house in West Hanney, Oxfordshire, owned by the mother of his girlfriend Nathania Simon.

When arrested in November 2011, three months after Duggan’s death, he denied any part in Easton’s murder.

At the Old Bailey his QC, Courtenay Griffiths, told the jury the bloodstains on his clothes “had nothing to do with him being a member of the attacking group — that had come about by the mere fact of his hat falling onto a blood stained surface.”

Mr Griffiths said Allen had used an alias at the hospital because he was scared he might lose custody of his children involved in on-going court proceedings.

Allen had gone on the run because he had heard from other sources there were people looking for him and the police had visited his address because they were concerned for his welfare, Mr Griffiths said.

Allen, 29, of Holloway, was found not guilty of murder by the jury after nearly 17-and-a-half hours of deliberations.

There were angry outbursts in the public gallery as the verdict was delivered, including shouts of “street justice”. Simon, 24, was convicted of one count of perverting the course of justice by lying to police but cleared of a second charge of providing the safe house for her boyfriend.

Simon said Allen had told her he feared for his life but did not tell her why, the court heard.